Preparation of aryl-substituted acetylenic compounds

ABSTRACT

ARYL-SUBSTITUTED ACETYLENIC COMPOUNDS ARE PREPARED BY REACTING ACETYLENE OR AN ARYLACETYLENE SUCH AS PHENYLACETYLENE WITH AN ORGANOPALLADIUM COMPOUND. THE LATTER COMPOUND IS PREPARED BY REACTING A PALLADIUM SALT SUCH AS PALLADIUM ACETATE WITH A SUITABLE ORGANOMERCURY, TIN OR LEAD COMPOUND, AS FOR EXAMPLE, DIPHENYLMERCURY, TETRAPHENYLTIN, TETRAPHENYLLEAD, PHENYLMERCURIC ACETATE.

United States Patent US. Cl. 260-469 Claims ABSTRACT OF THE DISCLOSUREAryl-substituted acetylenic compounds are prepared by reacting acetyleneor an arylacetylene such as phenylacetylene with an organopalladiumcompound. The latter compound is prepared by reacting a palladium saltsuch as palladium acetate with a suitable organomercury, tin or leadcompound as, for example, diphenylmercury, tetraphenyltin,tetraphenyllead, phenylmercuric acetate.

This invention relates to a process of preparing aryl-substitutedacetylenic compounds.

Many acetylenic compounds are readily prepared by known methods such asthe dehydrohalogenation of gem or vicinyl dihalides with strong basesunder vigorous contions or by the alkylation or carboxylation ofacetylenic' anions under basic conditions. These reactions are limitedto the production of acetylenic compounds that do not have basesensitive groups. In addition, in the first reaction, the necessarydihalides are often diflicult to obtain and during thedehydrohalogenation reaction, allenes or rearranged acetylenes, areoften produced instead of the desired acetylenic compound. In the secondof the above methods of preparation, the alkylations succeed only withunhindered and reactive alkylating agents.

Now in accordance with this invention, a process of preparingaryl-substituted acetylenes has been discovered which avoids theabove-mentioned complications. In the process of this invention,acetylene or a mono-aryl-substituted acetylene is reacted with anorganopalladium compound formed by reacting an organo-mercury, tin orlead compound with a palladium alkanoate. The reaction that takes placeis believed to take place by the following steps, using the acetatesalts for illustrative purposes:

Acetylenic compounds to which this reaction can be applied have theformula RCECH where R is H or aryl including substituted aryls, as forexample phenyl, tolyl, xylyl, p-isopropylphenyl, naphthyl, biphenylyl,pchlorophenyl, p-methoxyphenyl, p-carbomethoxyphenyl, nitronaphthyl,etc.

The organopalladium compound that is reacted with the acetyleniccompound can be preformed or formed in situ. Any palladium salt of acarboxylic acid can be used in preparing the organopalladium compoundsas, for example, palladium alkanoates such as palladium acetate,palladium propionate, palladium butyrate, or salts of aromaticcarboxylic acids such as palladium benzoate, palladium phthalate, etc.

The organo-mercury, -tin, or lead compound has the formula R' MY where Mis mercury, tin or lead and when M is mercury, x is 2 and n is 1 or 2and when M is tin or lead, x is 4 and n is 1, 2 or 3, R is an alkylradical of 1 to 12 carbon atoms, aryl, aralkyl, alkaryl, or asubstituted aryl wherein the substituents are alkoxy, halo,

nitro, hydroxy, aldehydo, carboxy or carboalkoxy, said alkoxy groupscontaining from 1 to 6 carbon atoms, said alkyl and aralkyl groupscontaining no hydrogen attached to the carbon beta to M, and Y is R or acarboxylic acid anion. Additionally, when M is mercury R' can becarboalkoxy where the alkoxy group contains 1 to 6 carbon atoms.Exemplary of these compounds are phenylmercuric acetate, phenylmercuricpropionate, phenylmercuric benzoate, xylylmercuric acetate,naphthylmercuric acetate. methylmercuric acetate, neopeutylmercuricacetate, 2,2- dimethylbutylmercuric acetate, 2,2-diethylbutylmercuricacetate, benzylmercuric acetate, cumylmercuric acetate, mesitylmercuricbenzoate, 3-nitrophenylmercuric acetate, S-carboxyphenylmercuricacetate, p-carbomethoxyphenylmercuric acetate,4-acetoxymercurisalicyladehyde, 3-nitrophenylmercuric acetate, panisylrnercuric acetate, diphenylmercury, di-p-tolylmercury,bis(p-chlorophenyl) mercury, dimethylmercury, dineopentylmercury,dibenzylmercury, etc., and the corresponding tin and lead compounds.Carboalkoxymercuric compounds that can be used are carbomethoxymercuricacetate, carboethoxymercuric acetate, carbopropoxymercuric acetate,carbobutoxymercuric acetate, carbohexoxymercuric acetate, etc.

The ratio of the palladium carboxylic acid salt to the organometalliccompound will preferably be one mole of palladium compound to eachorganic group in the organometallio compound. Thus, if theorganometallic is tetramethyltin, the ratio will be 4:1 and if theorganometallic is phenylmercuric acetate, the ratio will be 1:1.Obviously different ratios can be used, but this will generally leaveone reagent partly unreacted at the end of the reaction.

The acetylenic reactant is generally used in excess so that any sidereactions will occur with it rather than the product. The ratio of theacetylenic compound to the palladium compound can vary widely butgenerally will be from about 1:1 to about 20:1 or higher, and preferablywill be from about 2:1 to about 10:1.

The preparation of the arylacetylene compound will preferably be carriedout in an inert polar diluent as, for example, nitriles such asacetonitrile, propionitrile, benzonitrile, etc., ethers such as thedimethyl ether of diethylene glycol, the dimethyl ether of ethyleneglycol, etc., nitrocompounds such as nitrobenzene, chlorinatedhydrocarbons such as methylene chloride, etc.

The reaction is generally carried out at low temperature to avoidpolymerization of the acetylenic compound. A temperature of from about-25 C. up to C. can be used but preferably a temperature of from aboutl0 C. to about 50 C. is used. The reaction time required will, ofcourse, depend on the reaction conditions, but preferably will be asshort as possible to avoid subsequent reaction of the product in thereaction mixture.

The following examples will illustrate the process of this invention.

EXAMPLE 1 A mixture of 1.68 g. (5 mmoles) phenylmercuric acetate, 10 ml.of acetonitrile and 2 ml. (1.9 g.) of phenylacetylene was stirred at 0C. in an ice bath and 1.12 g. (5 mmoles) of powdered palladium acetatewas added. After stirring for 30 minutes at 0 C. the reaction wascontinued at room temperature for 15 hours. Analysis by gaschromatography then showed that 3.84 mmoles or 77% of theory based uponthe palladium acetate of diphenylacetylene had been produced.

EXAMPLE 2 The process of Example 1 was carried out with 5 mmoles ofp-anisylmercuric acetate in place of phenylmercuric acetate. There wasobtained 1-p-anisyl-2-phenylacetylene.

3 EXAMPLE 3 The process of Example 1 was carried out with 5 mmoles ofp-carbomethoxyphenylmercuric acetate in place of phenylmercuric acetateand l-p-carbomethoxyphenyl-Z-phenylacetylene was produced.

EXAMPLE 4 A 300 ml. glass vessel containing a magnetic stirring barcharged with 1.68 g. (5 mmoles) of phenylmercuric acetate and 1.15 g. (5mmoles) of powdered palladium acetate. The vessel was capped with aself-sealing rubber lined cap and then the air was replaced withnitrogen and then with acetylene by alternate evacuation and pressuring.The reaction mixture was stirred in an ice bath under 10 p.s.i.g. ofacetylene and 10 ml. of ice cold acetonitrile presaturated withacetylene under 10 p.s.i.g. was injected. After stirring for 30 minuteesat C., gas chr0- motatographic analysis showed that a 4% yield ofphenylacetylene had been obtained.

EXAMPLE The process of Example 1 was employed using 1.37 g. (5 moles) ofmethylmercuric acetate instead of phenylmercuric acetate. There wasobtained a 26% yield of 1- phenyl-l-propyne.

EXAMPLE 6 The process of Example 1 was used with 1.65 g. (5 mmoles) ofneopentylmercuric acetate in place of phenylmercuric acetate. Theproduct so obtained was l-neopentyI-Z-phenylacetylene.

EXAMPLE 7 The process of Example 1 was employed using 0.53 g. (1.25mmoles) of tetraphenyltin instead of the phenylmercuric acetate used inthat example. Diphenylacetylene was produced in good yield.

EXAMPLE 8 The process of Example 1 was employed using 0.64 g. (1.25mmoles) of tetraphenyllead instead of the phenylmercuric acetate used inthat example. A good yield of diphenylacetylene was obtained.

EXAMPLE 9 To a stirred mixture of 0.64 g. (2 mmoles)carbomethoxymercuric acetate, 10 ml. acetonitrile and 1.9 g. (2 ml.) ofphenylacetylene at 0 C., was added 0.45 g. (2 mmoles) of palladiumacetate. After stirring for 30 minutes at 0 C. and then for 16 hours atroom temperature, there was obtained a 41% yield of methyl 3-phenylpropiolate.

EXAMPLE 10 The process of Example 9 was used employing 1.28 g. (4 mmoles)of carbomethoxymercuric acetate instead of only 0.64 g. There wasobtained methyl 3-phenylpropiolate in 82% yield.

What I claim and desire to protect by Letters Patent is:

1. The process of preparing aryl-substituted acetylenic compounds whichcomprises contacting an acetylenic compound having the formula RCECHwhere R is H or an aryl radical at a temperature of from about 25 C. toabout C. with an organopalladium compound formed by reacting a palladiumsalt of a carboxylic acid with an organopalladium compound formed byreacting a palladium salt of a carboxylic acid with an organometalliccompound selected from (a) a compound having the formula R MY where M ismercury, tin or lead, and when M is mercury, x is 2 and n is 1 or 2, andwhen M is tin or lead, x is 4 and n is 1, 2 or 3, R alkyl containing 1to 12 carbon atoms, aryl, aralkyl, alkaryl or a substituted aryl whereinthe substituents are alkoxy, halo, nitro, hydroxy, aldehydo, carboxy orcarboalkoxy, said alkoxy groups containing from 1 to 6 carbon atoms, andY is R or a carboxylic acid anion, said alkyl and aralkyl containing nohydrogen on the carbon beta to M, or

(b) a carboalkoxymercuric alkanoate wherein the alkoxy group containsfrom 1 to 6 carbon atoms.

2. The process of claim 1 wherein the acetylenic compound having theformula R--CECH is acetylene.

3. The process of claim 1 wherein the acetylenic compound having theformula RCECH is phenylacetylene.

4. The process of claim 2 wherein the organopalladium compound is formedby reacting palladium acetate with phenylmercuric acetate.

5. The process of claim 3 wherein the organopalladium compound is formedby reacting palladium acetate with phenylmercuric acetate.

6. The process of claim 3 wherein the organopalladium compound is formedby reacting palladium acetate with p-anisylmercuric acetate.

7. The process of claim 3 wherein the organopalladium References CitedUNITED STATES PATENTS 4/1971 Heck 260671 9/1970 Heck 260--476 LORRAINEA. WEINBERGER, Primary Examiner R. D. KELLY, Assistant Examiner U.S. Cl.X.R.

260-476 R, 515 R, 599, 612 R, 612 D, 619 R, 621 R, 645, 649 R, 650 R,668 B, 671 A, 671 C Po-ww UNITED STATES PATENT ewes v CE'HMCATE CFCCRREC'HON Patent No. 3,751,446 Dated Auqust 7. 1973 Inventoflg) RichardF. I-leek (Case 32) It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 1, line 26 & 27, "contions" should read -condir,ions-- Column 2,line 15:, "4-acetoxymercurisalicyladehyde" should read-4acetoxymercurisalicylaldehyde Column 3, line 9, vinsert -was-,- after"bar" Column 4, lines 5 & 6, delete "organppalladium compound formed byreacting a palladium salt of a carboxylic acid with an" Column 4,(Cl. 1) line ll, insert -isafter "R' Signed and sealed this 20th day ofNovember 1973.

(SEAL) Attest:

EDWARD ,M.FLE TGHER,JR. RENE D. TEGTD IEYER Attesting Officer ActingCommissioner of Patents PO-l 050 Patent Nos Inventofls) Richard F. HeckCER'MHCATE @F RRETION Dated Auqust 7 1973 (Case 32) It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1,

Column 2,

Column 3,

Column 4,-

Column 4,

Signed (SEAL) Attest:

EDWARD M.FLET0H11R,JR. Attesting Officer 1 line 26 & 27, "contionsshould read -c0ndit;ions

line 15-, "4-acetoxymercurisalicyladehyde" should read-4acetoxymereurisalicylaldehyde line 9, insert -was after "bar" lines 5& 6, delete "organppalladium compound formed by reacting a palladiumsalt of a carboxylic acid with an" (C1,, 1) I line 11, insert is after"R' and sealed 'this 20th day of November 1973.

RENE D. TEGTMEYER Acting Commissioner of Patents

